排序方式: 共有9条查询结果,搜索用时 15 毫秒
1
1.
Superparamagnetic nanoparticles (NPs) are promising for biomedical applications since they can be directed toward the organ
of interest using an external magnetic field. They are also good contrast agents for magnetic resonance imaging and have potential
for the treatment of malignant tumors (i.e., hyperthermia). Therefore, there is a need to produce stable, non-aggregating
superparamagnetic nanomaterials that can withstand the in vivo environment. In this work, the colloidal stability of a dispersion
of iron oxide NPs was enhanced by functionalizing them with a short zwitterionic siloxane shell in aqueous media. The stabilization
procedure yields superparamagnetic nanomaterials, ca. 10 nm in diameter, with saturation magnetization of about 54 emu/g that
resist aggregation at physiological salt concentration, temperature, and pH. The loading of the zwitterionic shell was established
with diffuse reflectance infrared spectroscopy and thermal gravimetric analysis. X-ray and electron diffraction verified the
starting magnetite phase, and that no change in phase occurred on surface functionalization. 相似文献
2.
Layal Fahed Marc El Beyrouthy Naïm Ouaini Vronique Eparvier Didier Stien Sara Vitalini Marcello Iriti 《Molecules (Basel, Switzerland)》2021,26(21)
The chemical composition of Lebanese Hypericum scabrum essential oil (EO) was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GG-MS). Its antimicrobial activity was evaluated by determining its minimal inhibitory concentrations (MICs) against a Gram-negative and a Gram-positive bacterium, one yeast, and five dermatophytes. H. scabrum EO was most active on filamentous fungi (MIC values of 32–64 µg/mL). Synergy within the oil was investigated by testing each of the following major components on Trichophyton rubrum: α-pinene, limonene, myrcene, β-pinene and nonane, as well as a reconstructed EO. The antifungal activity of the natural oil could not be reached, meaning that its activity might be due, in part, to minor constituent(s). The interactions between H. scabrum EO and commercially available antifungals were assessed by the checkerboard test. A synergistic effect was revealed in the combination of the EO with amphotericin B. 相似文献
3.
4.
Layal Hariss Zeinab Barakat Farès Farès Thierry Roisnel René Grée Ali Hachem 《Tetrahedron letters》2019,60(3):292-296
Starting from easily accessible gem-difluoropropargylic derivatives a cascade nucleophilic substitution by N3–, followed by an intramolecular 1,3 dipolar cycloaddition, afforded in fair to good yields new 1,2,3-triazoles fused to pyrrolidines or piperidines. These molecules, with a gem-difluoro group vicinal to the triazoles, are fluorinated analogues of bioactive heterocycles. In parallel, a few open chain analogues have been prepared in order to evaluate the possible role of the bicyclic core on the biological properties of such molecules. 相似文献
5.
Narjara Gonzalez Suarez Sahily Rodriguez Torres Amira Ouanouki Layal El Cheikh-Hussein Borhane Annabi 《Molecules (Basel, Switzerland)》2021,26(6)
Obese subjects have an increased risk of developing triple-negative breast cancer (TNBC), in part associated with the chronic low-grade inflammation state. On the other hand, epidemiological data indicates that increased consumption of polyphenol-rich fruits and vegetables plays a key role in reducing incidence of some cancer types. Here, we tested whether green tea-derived epigallocatechin-3-gallate (EGCG) could alter adipose-derived mesenchymal stem cell differentiation into adipocytes, and how this impacts the secretome profile and paracrine regulation of the TNBC invasive phenotype. Here, cell differentiation was performed and conditioned media (CM) from preadipocytes and mature adipocytes harvested. Human TNBC-derived MDA-MB-231 real-time cell migration was performed using the exCELLigence system. Differential gene arrays and RT-qPCR were used to assess gene expression levels. Western blotting was used to assess protein expression and phosphorylation status levels. In vitro vasculogenic mimicry (VM) was assessed with Matrigel. EGCG was found to inhibit the induction of key adipogenic biomarkers, including lipoprotein lipase, adiponectin, leptin, fatty acid synthase, and fatty acid binding protein 4. Increased TNBC-derived MDA-MB-231 cell chemotaxis and vasculogenic mimicry were observed in response to mature adipocytes secretome, and this was correlated with increased STAT3 phosphorylation status. This invasive phenotype was prevented by EGCG, the JAK/STAT inhibitors Tofacitinib and AG490, as well as upon STAT3 gene silencing. In conclusion, dietary catechin-mediated interventions could, in part through the inhibition of adipogenesis and modulation of adipocytes secretome profile, prevent the onset of an obesogenic environment that favors TNBC development. 相似文献
6.
Layal Hakim Guilhem Lacaze Mohammad Khalil Khachik Sargsyan Habib Najm Joseph Oefelein 《Combustion Theory and Modelling》2018,22(3):446-466
This paper demonstrates the development of a simple chemical kinetics model designed for autoignition of n-dodecane in air using Bayesian inference with a model-error representation. The model error, i.e. intrinsic discrepancy from a high-fidelity benchmark model, is represented by allowing additional variability in selected parameters. Subsequently, we quantify predictive uncertainties in the results of autoignition simulations of homogeneous reactors at realistic diesel engine conditions. We demonstrate that these predictive error bars capture model error as well. The uncertainty propagation is performed using non-intrusive spectral projection that can also be used in principle with larger scale computations, such as large eddy simulation. While the present calibration is performed to match a skeletal mechanism, it can be done with equal success using experimental data only (e.g. shock-tube measurements). Since our method captures the error associated with structural model simplifications, we believe that the optimised model could then lead to better qualified predictions of autoignition delay time in high-fidelity large eddy simulations than the existing detailed mechanisms. This methodology provides a way to reduce the cost of reaction kinetics in simulations systematically, while quantifying the accuracy of predictions of important target quantities. 相似文献
7.
Rouhana LL Jaber JA Schlenoff JB 《Langmuir : the ACS journal of surfaces and colloids》2007,23(26):12799-12801
Stable, water-soluble gold nanoparticles, Au NPs, having an average diameter of ca. 4 nm, were prepared using place exchange reactions. The nanoparticles, capped with novel zwitterionic disulfide ligands, showed remarkable stability in saline media with salt concentrations as high as 3.0 M. Similarly, the Au NPs did not precipitate out of solution when charged polyelectrolytes or biopolymers were added, indicating the absence of nonspecific interactions. The stability and degree of association of Au NPs were characterized using UV-vis absorption spectroscopy, quasi-elastic light scattering, and surface-enhanced Raman scattering. 相似文献
8.
Rouhana LL Moussallem MD Schlenoff JB 《Journal of the American Chemical Society》2011,133(40):16080-16091
The adsorption of water-soluble alkane thiols and their corresponding disulfides onto gold was followed in real time using highly sensitive surface conductivity measurements. Particular attention was paid to producing clean surfaces and to the purity of the adsorbates. The rate of mass transport to the surface was constant, controlled, and measured, over the whole time course of the experiment (1-10(4) s), by convective diffusion. An adsorption rate equation derived for coupled steady state convective-diffusion mass transport and Langmuir kinetics shows that systems limited by mass transport must also be slowed by Langmuir kinetics. Thiols and disulfides adsorbed at the same rate, limited mainly by mass transport. The distinct slowdown in adsorption rate for longer alkanethiols, attributed to conformational transitions (lying down → standing up), was less evident for the neutral thiols/disulfides. The slower rate of charged thiol adsorption is thought to stem from steric interactions of large, hydrated tail groups, although calcium as a counterion accelerated monolayer formation. The adsorption kinetics of a charged thiol were almost the same under screened (by extra added salt) or unscreened conditions. Therefore, long-range electrostatic interactions appear to be less important than short-range steric ones in limiting adsorption rates at surfaces. 相似文献
9.
1